French rail officials say Friday's deadly train derailment at a station south of Paris may have been caused by a detached rail joint on the track.

An official with the national rail company, SNCF, Pierre Izard, said Saturday the metal component came loose from its normal position at a track switching point at Bretigny-sur-Orge station that links two rails. The official said the piece moved into the center of the switch, preventing the train's wheels from passing through normally.

The train, on its way from Paris to the city of Limoges, veered off track Friday and crashed into the platform at Bretigny-sur-Orge, about 20 kilometers south of the French capital. The station was not a scheduled stop. Some 385 passengers were on the train when it crashed. At least six were killed and dozens more injured.

French Transport Minister Frederic Cuvillier has said human error was not to blame for the accident. Cuvillier praised the train engineer, telling French radio Saturday that the engineer's quick action prevented a collision with another train - and a much worse accident - by only seconds.

A large crane was being used Saturday to clear the wreckage from the accident, including at least one train car that fell onto its side. Officials have said they do not know if there could be any other people trapped underneath it.

Friday's accident occurred as many families were traveling for summer vacations. This is a holiday weekend in France, which celebrates its most important national holiday - Bastille Day - on Sunday.

Train stations throughout France held a minute of silence Saturday at noon for the victims of the accident.